RE: "Can anyone recommend a shop in the LA area for crack checking spindles, trailing arms etc...?"
We do that here at AMD but were not in the LA area. If you do find a mag shop down in LA be sure they are familiar with the way the loads are applied to the parts that are to be inspected. Sometimes questionable indications are simply declared cracked and rejected just to cover their a$$es for liability when there is no reason for the part to be rejected. In most cases it is still serviceable.
"I know it all, but I can't remember most of it..."
Thanks for the advice Dave, I know what you mean. I had my local machine shop mag the arms last year. He gave them back to us saying there was a crack at just about every weld. Brought it up to Foddrill and they told us it was normal to have the "appearance" of cracks a the edges of the weld. I'm glad we checked with them first before buying new arms. I am hoping to find someone around here that can do it and is familiar with our sport like you said.
Look up "Non destructive testing" in the yellows. Aircraft parts are inspected with some degree of regularity that Dave G would know better than I. Here in Ventura is Western Aerospace. At least I think that's their name, they're btwn Fast Undercar & Nat'l Parts Depot.
"It only seems kinky the first time"
-- Bumpersticker seen in Lost Wages
or better yet-The Thomas Register, The big Blue, Yellow, and/or Red labeled (green hardback) books you buy every couple of years that list every name of every product and/or manufacturer on this planet! Good books to own!
<font color=red>"Quality has no fear of Time"</font color=red>